The saline-alkali wastelands along Bohai Bay were once covered in salty mud and plagued by rampant insect infestations. Nobody believed this barren land could ever produce wealth. Lin Fan, an agricultural university graduate, returns to his hometown to start a business. Despite the entire village questioning him, he introduces an ecological rice-crab co-cultivation system and makes a bet with the stubborn villagers over its output value. Initially, severe pest infestations bring him endless ridicule. But by improving crab seedlings from the Liaohe River estuary and installing black-light insect traps, he creates a closed-loop ecological system in which crabs eliminate pests and crab manure fertilizes the rice fields.